What's that noise???

Anyone know what the noise is that is distracting Novak??? Sounds like someone popping bubble-rap over a speaker. It's really loud

(I know this is a men's match, but I am interested to know what the noise is, not anything about the match itself.)

One of the loud speakers was giving feedback.

One of the loud speakers was giving feedback.

oh ok. i thought they were saying "why does he have to do that now?", must have been "it", not "he"